Add Dynamic Content to email header\footer

My marketing emails is on 4 different languages (English, French, Italian and Arab),

and all my emails are built with dynamic content based on the Language field of the contact.

Unfortunately there is no way to add dynamic content to header\footer of an email for example the view online version on the email header or the "unsubscribe sentence" on the email footer.

My workaround is the add those to the email body and leave the header and footer blank.

I hope the spam mechanism of gmail don't check the header and footer as well.